Team develop wireless, dissolvable sensors to monitor intracranial pressure and temperature

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Dissolvable wireless brain sensors to monitor intracranial pressure and temperature have been developed by a team of neurosurgeons and engineers.

The implants, which can be absorbed by the body, have been developed by scientists at Washington University School of Medicine in St. Louis, USA, and engineers at the University of Illinois at Urbana-Champaign, USA. It is hoped that could potentially be used to monitor patients with traumatic brain injuries, but the researchers believe they can build similar absorbable sensors to monitor activity in organ systems throughout the body. Their findings are published online in Nature.

Rory KJ Murphy, co-first author and a neurosurgery resident at Washington University School of Medicine and Barnes-Jewish Hospital in St Louis, USA, is interested in monitoring pressure and temperature in the brains of patients with traumatic brain injury.

 “The devices commonly used today are based on technology from the 1980s,” Murphy explained. “They’re large, they’re unwieldy, and they have wires that connect to monitors in the intensive care unit. They give accurate readings, and they help, but there are ways to make them better.”

Murphy collaborated with engineers in the laboratory of John A Rogers, a professor of materials science and engineering at the University of Illinois, to build new sensors. The devices are made mainly of polylactic-co-glycolic acid (PLGA) and silicone, and they can transmit accurate pressure and temperature readings, as well as other information.

“With advanced materials and device designs, we demonstrated that it is possible to create electronic implants that offer high performance and clinically relevant operation in hardware that completely resorbs into the body after the relevant functions are no longer needed,” Rogers said. “This type of bio-electric medicine has great potential in many areas of clinical care.”

The researchers tested the sensors in baths of saline solution that caused them to dissolve after a few days. Next, they tested the devices in the brains of laboratory rats.

Having shown that the sensors are accurate, and that they dissolve in the solution and in the brains of rats, the researchers now are planning to test the technology in patients.

“In terms of the major challenges involving size and scale, we’ve already crossed some key bridges,” said co-senior author Wilson Z Ray, assistant professor of neurological and orthopaedic surgery at Washington University.

“The ultimate strategy is to have a device that you can place in the brain — or in other organs in the body — that is entirely implanted, intimately connected with the organ you want to monitor and can transmit signals wirelessly to provide information on the health of that organ, allowing doctors to intervene if necessary to prevent bigger problems,” Murphy said. “And then after the critical period that you actually want to monitor, it will dissolve away and disappear.”

Funding for this research comes from the National Institute of Mental Health of the National Institutes of Health (NIH), grant number F31 MH101956. Additional funding comes from the Defense Advanced Research Projects Agency and the Howard Hughes Medical Institute.